Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6.git] / drivers / net / eql.c
1 /*
2  * Equalizer Load-balancer for serial network interfaces.
3  *
4  * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
5  * NCM: Network and Communications Management, Inc.
6  *
7  * (c) Copyright 2002 David S. Miller (davem@redhat.com)
8  *
9  *      This software may be used and distributed according to the terms
10  *      of the GNU General Public License, incorporated herein by reference.
11  *
12  * The author may be reached as simon@ncm.com, or C/O
13  *    NCM
14  *    Attn: Simon Janes
15  *    6803 Whittier Ave
16  *    McLean VA 22101
17  *    Phone: 1-703-847-0040 ext 103
18  */
19
20 /*
21  * Sources:
22  *   skeleton.c by Donald Becker.
23  * Inspirations:
24  *   The Harried and Overworked Alan Cox
25  * Conspiracies:
26  *   The Alan Cox and Mike McLagan plot to get someone else to do the code,
27  *   which turned out to be me.
28  */
29
30 /*
31  * $Log: eql.c,v $
32  * Revision 1.2  1996/04/11 17:51:52  guru
33  * Added one-line eql_remove_slave patch.
34  *
35  * Revision 1.1  1996/04/11 17:44:17  guru
36  * Initial revision
37  *
38  * Revision 3.13  1996/01/21  15:17:18  alan
39  * tx_queue_len changes.
40  * reformatted.
41  *
42  * Revision 3.12  1995/03/22  21:07:51  anarchy
43  * Added capable() checks on configuration.
44  * Moved header file.
45  *
46  * Revision 3.11  1995/01/19  23:14:31  guru
47  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
48  *                      (priority_Bps) + bytes_queued * 8;
49  *
50  * Revision 3.10  1995/01/19  23:07:53  guru
51  * back to
52  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
53  *                      (priority_Bps) + bytes_queued;
54  *
55  * Revision 3.9  1995/01/19  22:38:20  guru
56  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
57  *                      (priority_Bps) + bytes_queued * 4;
58  *
59  * Revision 3.8  1995/01/19  22:30:55  guru
60  *       slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
61  *                      (priority_Bps) + bytes_queued * 2;
62  *
63  * Revision 3.7  1995/01/19  21:52:35  guru
64  * printk's trimmed out.
65  *
66  * Revision 3.6  1995/01/19  21:49:56  guru
67  * This is working pretty well. I gained 1 K/s in speed.. now it's just
68  * robustness and printk's to be diked out.
69  *
70  * Revision 3.5  1995/01/18  22:29:59  guru
71  * still crashes the kernel when the lock_wait thing is woken up.
72  *
73  * Revision 3.4  1995/01/18  21:59:47  guru
74  * Broken set-bit locking snapshot
75  *
76  * Revision 3.3  1995/01/17  22:09:18  guru
77  * infinite sleep in a lock somewhere..
78  *
79  * Revision 3.2  1995/01/15  16:46:06  guru
80  * Log trimmed of non-pertinent 1.x branch messages
81  *
82  * Revision 3.1  1995/01/15  14:41:45  guru
83  * New Scheduler and timer stuff...
84  *
85  * Revision 1.15  1995/01/15  14:29:02  guru
86  * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
87  * with the dumber scheduler
88  *
89  * Revision 1.14  1995/01/15  02:37:08  guru
90  * shock.. the kept-new-versions could have zonked working
91  * stuff.. shudder
92  *
93  * Revision 1.13  1995/01/15  02:36:31  guru
94  * big changes
95  *
96  *      scheduler was torn out and replaced with something smarter
97  *
98  *      global names not prefixed with eql_ were renamed to protect
99  *      against namespace collisions
100  *
101  *      a few more abstract interfaces were added to facilitate any
102  *      potential change of datastructure.  the driver is still using
103  *      a linked list of slaves.  going to a heap would be a bit of
104  *      an overkill.
105  *
106  *      this compiles fine with no warnings.
107  *
108  *      the locking mechanism and timer stuff must be written however,
109  *      this version will not work otherwise
110  *
111  * Sorry, I had to rewrite most of this for 2.5.x -DaveM
112  */
113
114 #include <linux/capability.h>
115 #include <linux/module.h>
116 #include <linux/kernel.h>
117 #include <linux/init.h>
118 #include <linux/timer.h>
119 #include <linux/netdevice.h>
120 #include <net/net_namespace.h>
121
122 #include <linux/if.h>
123 #include <linux/if_arp.h>
124 #include <linux/if_eql.h>
125
126 #include <asm/uaccess.h>
127
128 static int eql_open(struct net_device *dev);
129 static int eql_close(struct net_device *dev);
130 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
131 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
132
133 #define eql_is_slave(dev)       ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
134 #define eql_is_master(dev)      ((dev->flags & IFF_MASTER) == IFF_MASTER)
135
136 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
137
138 static void eql_timer(unsigned long param)
139 {
140         equalizer_t *eql = (equalizer_t *) param;
141         struct list_head *this, *tmp, *head;
142
143         spin_lock_bh(&eql->queue.lock);
144         head = &eql->queue.all_slaves;
145         list_for_each_safe(this, tmp, head) {
146                 slave_t *slave = list_entry(this, slave_t, list);
147
148                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
149                         slave->bytes_queued -= slave->priority_Bps;
150                         if (slave->bytes_queued < 0)
151                                 slave->bytes_queued = 0;
152                 } else {
153                         eql_kill_one_slave(&eql->queue, slave);
154                 }
155
156         }
157         spin_unlock_bh(&eql->queue.lock);
158
159         eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
160         add_timer(&eql->timer);
161 }
162
163 static const char version[] __initconst =
164         "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
165
166 static const struct net_device_ops eql_netdev_ops = {
167         .ndo_open       = eql_open,
168         .ndo_stop       = eql_close,
169         .ndo_do_ioctl   = eql_ioctl,
170         .ndo_start_xmit = eql_slave_xmit,
171 };
172
173 static void __init eql_setup(struct net_device *dev)
174 {
175         equalizer_t *eql = netdev_priv(dev);
176
177         init_timer(&eql->timer);
178         eql->timer.data         = (unsigned long) eql;
179         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
180         eql->timer.function     = eql_timer;
181
182         spin_lock_init(&eql->queue.lock);
183         INIT_LIST_HEAD(&eql->queue.all_slaves);
184         eql->queue.master_dev   = dev;
185
186         dev->netdev_ops         = &eql_netdev_ops;
187
188         /*
189          *      Now we undo some of the things that eth_setup does
190          *      that we don't like
191          */
192
193         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in if_eql.h */
194         dev->flags              = IFF_MASTER;
195
196         dev->type               = ARPHRD_SLIP;
197         dev->tx_queue_len       = 5;            /* Hands them off fast */
198         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
199 }
200
201 static int eql_open(struct net_device *dev)
202 {
203         equalizer_t *eql = netdev_priv(dev);
204
205         /* XXX We should force this off automatically for the user. */
206         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
207                "your slave devices.\n", dev->name);
208
209         BUG_ON(!list_empty(&eql->queue.all_slaves));
210
211         eql->min_slaves = 1;
212         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
213
214         add_timer(&eql->timer);
215
216         return 0;
217 }
218
219 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
220 {
221         list_del(&slave->list);
222         queue->num_slaves--;
223         slave->dev->flags &= ~IFF_SLAVE;
224         dev_put(slave->dev);
225         kfree(slave);
226 }
227
228 static void eql_kill_slave_queue(slave_queue_t *queue)
229 {
230         struct list_head *head, *tmp, *this;
231
232         spin_lock_bh(&queue->lock);
233
234         head = &queue->all_slaves;
235         list_for_each_safe(this, tmp, head) {
236                 slave_t *s = list_entry(this, slave_t, list);
237
238                 eql_kill_one_slave(queue, s);
239         }
240
241         spin_unlock_bh(&queue->lock);
242 }
243
244 static int eql_close(struct net_device *dev)
245 {
246         equalizer_t *eql = netdev_priv(dev);
247
248         /*
249          *      The timer has to be stopped first before we start hacking away
250          *      at the data structure it scans every so often...
251          */
252
253         del_timer_sync(&eql->timer);
254
255         eql_kill_slave_queue(&eql->queue);
256
257         return 0;
258 }
259
260 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
261 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
262
263 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
264 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
265
266 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
267 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
268
269 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
270 {
271         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
272             !capable(CAP_NET_ADMIN))
273                 return -EPERM;
274
275         switch (cmd) {
276                 case EQL_ENSLAVE:
277                         return eql_enslave(dev, ifr->ifr_data);
278                 case EQL_EMANCIPATE:
279                         return eql_emancipate(dev, ifr->ifr_data);
280                 case EQL_GETSLAVECFG:
281                         return eql_g_slave_cfg(dev, ifr->ifr_data);
282                 case EQL_SETSLAVECFG:
283                         return eql_s_slave_cfg(dev, ifr->ifr_data);
284                 case EQL_GETMASTRCFG:
285                         return eql_g_master_cfg(dev, ifr->ifr_data);
286                 case EQL_SETMASTRCFG:
287                         return eql_s_master_cfg(dev, ifr->ifr_data);
288                 default:
289                         return -EOPNOTSUPP;
290         };
291 }
292
293 /* queue->lock must be held */
294 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
295 {
296         unsigned long best_load = ~0UL;
297         struct list_head *this, *tmp, *head;
298         slave_t *best_slave;
299
300         best_slave = NULL;
301
302         /* Make a pass to set the best slave. */
303         head = &queue->all_slaves;
304         list_for_each_safe(this, tmp, head) {
305                 slave_t *slave = list_entry(this, slave_t, list);
306                 unsigned long slave_load, bytes_queued, priority_Bps;
307
308                 /* Go through the slave list once, updating best_slave
309                  * whenever a new best_load is found.
310                  */
311                 bytes_queued = slave->bytes_queued;
312                 priority_Bps = slave->priority_Bps;
313                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
314                         slave_load = (~0UL - (~0UL / 2)) -
315                                 (priority_Bps) + bytes_queued * 8;
316
317                         if (slave_load < best_load) {
318                                 best_load = slave_load;
319                                 best_slave = slave;
320                         }
321                 } else {
322                         /* We found a dead slave, kill it. */
323                         eql_kill_one_slave(queue, slave);
324                 }
325         }
326         return best_slave;
327 }
328
329 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
330 {
331         equalizer_t *eql = netdev_priv(dev);
332         slave_t *slave;
333
334         spin_lock(&eql->queue.lock);
335
336         slave = __eql_schedule_slaves(&eql->queue);
337         if (slave) {
338                 struct net_device *slave_dev = slave->dev;
339
340                 skb->dev = slave_dev;
341                 skb->priority = 1;
342                 slave->bytes_queued += skb->len;
343                 dev_queue_xmit(skb);
344                 dev->stats.tx_packets++;
345         } else {
346                 dev->stats.tx_dropped++;
347                 dev_kfree_skb(skb);
348         }
349
350         spin_unlock(&eql->queue.lock);
351
352         return NETDEV_TX_OK;
353 }
354
355 /*
356  *      Private ioctl functions
357  */
358
359 /* queue->lock must be held */
360 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
361 {
362         struct list_head *this, *head;
363
364         head = &queue->all_slaves;
365         list_for_each(this, head) {
366                 slave_t *slave = list_entry(this, slave_t, list);
367
368                 if (slave->dev == dev)
369                         return slave;
370         }
371
372         return NULL;
373 }
374
375 static inline int eql_is_full(slave_queue_t *queue)
376 {
377         equalizer_t *eql = netdev_priv(queue->master_dev);
378
379         if (queue->num_slaves >= eql->max_slaves)
380                 return 1;
381         return 0;
382 }
383
384 /* queue->lock must be held */
385 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
386 {
387         if (!eql_is_full(queue)) {
388                 slave_t *duplicate_slave = NULL;
389
390                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
391                 if (duplicate_slave)
392                         eql_kill_one_slave(queue, duplicate_slave);
393
394                 list_add(&slave->list, &queue->all_slaves);
395                 queue->num_slaves++;
396                 slave->dev->flags |= IFF_SLAVE;
397
398                 return 0;
399         }
400
401         return -ENOSPC;
402 }
403
404 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
405 {
406         struct net_device *slave_dev;
407         slaving_request_t srq;
408
409         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
410                 return -EFAULT;
411
412         slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
413         if (slave_dev) {
414                 if ((master_dev->flags & IFF_UP) == IFF_UP) {
415                         /* slave is not a master & not already a slave: */
416                         if (!eql_is_master(slave_dev) &&
417                             !eql_is_slave(slave_dev)) {
418                                 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
419                                 equalizer_t *eql = netdev_priv(master_dev);
420                                 int ret;
421
422                                 if (!s) {
423                                         dev_put(slave_dev);
424                                         return -ENOMEM;
425                                 }
426
427                                 memset(s, 0, sizeof(*s));
428                                 s->dev = slave_dev;
429                                 s->priority = srq.priority;
430                                 s->priority_bps = srq.priority;
431                                 s->priority_Bps = srq.priority / 8;
432
433                                 spin_lock_bh(&eql->queue.lock);
434                                 ret = __eql_insert_slave(&eql->queue, s);
435                                 if (ret) {
436                                         dev_put(slave_dev);
437                                         kfree(s);
438                                 }
439                                 spin_unlock_bh(&eql->queue.lock);
440
441                                 return ret;
442                         }
443                 }
444                 dev_put(slave_dev);
445         }
446
447         return -EINVAL;
448 }
449
450 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
451 {
452         equalizer_t *eql = netdev_priv(master_dev);
453         struct net_device *slave_dev;
454         slaving_request_t srq;
455         int ret;
456
457         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
458                 return -EFAULT;
459
460         slave_dev = dev_get_by_name(&init_net, srq.slave_name);
461         ret = -EINVAL;
462         if (slave_dev) {
463                 spin_lock_bh(&eql->queue.lock);
464
465                 if (eql_is_slave(slave_dev)) {
466                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
467                                                               slave_dev);
468
469                         if (slave) {
470                                 eql_kill_one_slave(&eql->queue, slave);
471                                 ret = 0;
472                         }
473                 }
474                 dev_put(slave_dev);
475
476                 spin_unlock_bh(&eql->queue.lock);
477         }
478
479         return ret;
480 }
481
482 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
483 {
484         equalizer_t *eql = netdev_priv(dev);
485         slave_t *slave;
486         struct net_device *slave_dev;
487         slave_config_t sc;
488         int ret;
489
490         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
491                 return -EFAULT;
492
493         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
494         if (!slave_dev)
495                 return -ENODEV;
496
497         ret = -EINVAL;
498
499         spin_lock_bh(&eql->queue.lock);
500         if (eql_is_slave(slave_dev)) {
501                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
502                 if (slave) {
503                         sc.priority = slave->priority;
504                         ret = 0;
505                 }
506         }
507         spin_unlock_bh(&eql->queue.lock);
508
509         dev_put(slave_dev);
510
511         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
512                 ret = -EFAULT;
513
514         return ret;
515 }
516
517 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
518 {
519         slave_t *slave;
520         equalizer_t *eql;
521         struct net_device *slave_dev;
522         slave_config_t sc;
523         int ret;
524
525         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
526                 return -EFAULT;
527
528         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
529         if (!slave_dev)
530                 return -ENODEV;
531
532         ret = -EINVAL;
533
534         eql = netdev_priv(dev);
535         spin_lock_bh(&eql->queue.lock);
536         if (eql_is_slave(slave_dev)) {
537                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
538                 if (slave) {
539                         slave->priority = sc.priority;
540                         slave->priority_bps = sc.priority;
541                         slave->priority_Bps = sc.priority / 8;
542                         ret = 0;
543                 }
544         }
545         spin_unlock_bh(&eql->queue.lock);
546
547         dev_put(slave_dev);
548
549         return ret;
550 }
551
552 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
553 {
554         equalizer_t *eql;
555         master_config_t mc;
556
557         if (eql_is_master(dev)) {
558                 eql = netdev_priv(dev);
559                 mc.max_slaves = eql->max_slaves;
560                 mc.min_slaves = eql->min_slaves;
561                 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
562                         return -EFAULT;
563                 return 0;
564         }
565         return -EINVAL;
566 }
567
568 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
569 {
570         equalizer_t *eql;
571         master_config_t mc;
572
573         if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
574                 return -EFAULT;
575
576         if (eql_is_master(dev)) {
577                 eql = netdev_priv(dev);
578                 eql->max_slaves = mc.max_slaves;
579                 eql->min_slaves = mc.min_slaves;
580                 return 0;
581         }
582         return -EINVAL;
583 }
584
585 static struct net_device *dev_eql;
586
587 static int __init eql_init_module(void)
588 {
589         int err;
590
591         printk(version);
592
593         dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
594         if (!dev_eql)
595                 return -ENOMEM;
596
597         err = register_netdev(dev_eql);
598         if (err)
599                 free_netdev(dev_eql);
600         return err;
601 }
602
603 static void __exit eql_cleanup_module(void)
604 {
605         unregister_netdev(dev_eql);
606         free_netdev(dev_eql);
607 }
608
609 module_init(eql_init_module);
610 module_exit(eql_cleanup_module);
611 MODULE_LICENSE("GPL");